Improved electric energy density and conversion efficiency of natural rubber composites as dielectric elastomer generators

Abstract

Dielectric elastomer generators (DEGs), which can harvest energy from environmental sources, have gained considerable research attention over the past few decades. However, the current dielectric elastomers exhibit low electric energy density and conversion efficiency, which limit their practical application. Herein, the electric energy density and conversion efficiency of natural rubber (NR) composites have been enhanced by adding of barium titanate (BT) nanoparticles and dioctyl phthalate (DOP) plasticizer in NR matrix. Due to the synergistic effect of BT and DOP, a high dielectric constant and a low elastic modulus are exhibited by NR composites, which can be attributed to the adjusting of filler network and polymeric intermolecular attractions. The as-prepared BT/DOP/NR composites have exhibited an enhanced harvested electric energy density of 0.71 mJ/cm3 and energy conversion efficiency of 3.8%, which are ∼3.8 and 4.7 times higher than pure NR, respectively. In addition, the as-prepared NR composites exhibit excellent actuation properties, which indicate that these composites have great potential in a wide range of applications, such as energy harvesters and soft sensors.

Enhancement of electromechanical properties of natural rubber by adding barium titanate filler: An electro‐mechanical study

“…The addition of fillers increases the dielectric breakdown strength of NR/BT composites. Increasing filler content network in polymer chain matrix decreased mobility of NR chains because they are being constrained by tightly bonded filler nanoparticles and hence, charged are not being carried away which results in enhancement of the dielectric breakdown strength that is also reported by Yung et al 43 …”

“…From Table 5, we observed that as the filler content increases, dielectric constant values of the NR/BT composite increase as shown by these works. Yung et al 43 observed an increase in dielectric constant of NR/BT composites from 3.2 to 3.6 with filler content from 0 to 50 phr, respectively at 100 Hz. With respect to these work we observed better dielectric constant of NR/BT composite with 4.2 at 1 Hz.…”

Dielectric Elastomer Generator for Electromechanical Energy Conversion: A Mini Review

“…For example, we can regulate the stress-strain response of the elastomers, which can reduce hysteresis loss. We can also increase the relative dielectric constant [48,49], which can raise the energy density of a material. The output performance of materials is crucial for DEG applications.…”

Optimizing energy harvesting performance of silicone elastomers by molecular grafting of azobenzene to the macromolecular network

“…For instance, BaTiO 3 nanoparticles and dioctyl phthalate (DOP) plasticizer were simultaneously added into the natural rubber matrix by Zhang's group. 13 The as-prepared composite exhibited improved performances involving electric energy density (0.71 mJ cm À3 ) and energy conversion efficiency (3.8%) comparing with pure natural rubber. Another commonly adopted approach to increase the dielectric permittivity is the incorporation of conductive llers such as metallic particles and carbon nanomaterial.…”